Semiconductor device and control method thereof

1. A semiconductor device comprising: a substrate of the semiconductor device divided into a plurality of area each of which is provided with a clock adjusting unit, a skew detecting unit, and a clock distributing unit; a clock supplying unit supplying a first clock; a clock distributing unit being inputted a delay set value and the first clock, outputting a second clock obtained by changing a phase of the inputted first clock based on the inputted delay set value, and supplying the second clock to circuits provided in an area to which the clock distributing unit belongs; a skew detecting unit detecting at least one over delay path or racing path, one of an input unit and an output unit of the over delay path or racing path is provided in an area to which the skew detecting unit belongs, and the other of the input unit and the output unit of the over delay path or racing path is provided in an area to which the skew detecting unit does not belong, and detecting skew in the over delay path or racing path; and a clock adjusting unit setting a value of delay based on the skew detected by the skew detecting unit.

2. The semiconductor device according to claim 1 , wherein the skew detecting unit detects a plurality of over delay paths or racing paths in the semiconductor device, and wherein the clock adjusting unit further comprises a decision by majority circuit which sets an increase or decrease of the set value of the delay based on decision by majority of skew detected on the plurality of over delay paths or racing paths.

3. The semiconductor device according to claim 1 , wherein the clock adjusting units provided in the plurality of areas are connected to form a chain circuit for setting an initial value of the set value of the delay, and the chain circuit is connected between an input terminal and an output terminal of the semiconductor device.

4. A control method for a semiconductor device operating according to supply of clock to an inside thereof, the control method comprising: providing a substrate of the semiconductor device divided into a plurality of area each of which is provided with a clock adjusting unit, a skew detecting unit, and a clock distributing unit; supplying a first clock form the clock supplying unit; inputting a delay set value and the first clock to the clock distributing unit, and outputting a second clock obtained by changing a phase of the input first clock based on the delay set value from the clock distributing unit; supplying the second clock from the clock distributing unit to circuits provided in an area to which the clock distributing unit belongs; detecting in the skew detecting unit at least one over delay path or racing path, one of an input unit and an output unit of the over delay path or racing path is provided in an area to which the skew detecting unit belongs, and the other of the input unit and the output unit of the over delay path or racing path is provided in an area to which the skew detecting unit does not belong; detecting in the skew detecting unit skew in the over delay path or racing path; and setting in the clock adjusting unit a value of delay based on the skew detected by the skew detecting unit.